After upgrading ProxySG-S500 from 220.127.116.11 to 18.104.22.168, some ports on the Proxy did not come up. The Switch connected to the Proxy disabled the ports by Spanning Tree Protocol.
This applies to SG-S400 and SG-S500 with a bridge card.
The above issue is a known issue. It has been fixed in 22.214.171.124 and 126.96.36.199. Here is what we mentioned in the Release Notes:
TCP/IP and General Networking
SG-32241 Fixes an issue in S400 and S500 hardware environments with a bridge card, where a disabled bridge became enabled during boot and caused switches with STP to disable ports.
Please upgrade to 188.8.131.52 or 184.108.40.206 and above to fix the issue.
Note: You may be able to toggle (enable and disable) the bridge as a temporary workaround. This should work until the next reboot, however, upgrade is highly recommended.